📄 index.html
字号:
<!DOCTYPE HTML PUBLIC "html.dtd"><HTML><HEAD><TITLE>Presenting XML:index:EarthWeb Inc.-</TITLE><META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"><SCRIPT><!--function displayWindow(url, width, height) { var Win = window.open(url,"displayWindow",'width=' + width +',height=' + height + ',resizable=1,scrollbars=yes');}//--></SCRIPT></HEAD><BODY BGCOLOR="#FFFFFF" VLINK="#DD0000" TEXT="#000000" LINK="#DD0000" ALINK="#FF0000"><TD WIDTH="540" VALIGN="TOP"><!-- <CENTER><TABLE><TR><TD><FORM METHOD="GET" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-foldocsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE="Glossary Search"></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD><TD><IMG SRC="http://www.itknowledge.com/images/dotclear.gif" WIDTH="15" HEIGHT="1"></TD><TD><FORM METHOD="POST" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-subscriptionsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE=" Book Search "></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="backlink" TYPE="hidden" VALUE="http://search.itknowledge.com:80/excite/AT-subscriptionquery.html"><INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD></TR></TABLE></CENTER> --><!-- ISBN=1575213346 //--><!-- TITLE=Presenting XML//--><!-- AUTHOR=Richard Light//--><!-- PUBLISHER=Macmillan Computer Publishing//--><!-- IMPRINT=Sams//--><!-- CHAPTER=index //--><!-- PAGES=393 //--><!-- UNASSIGNED1 //--><!-- UNASSIGNED2 //--><P><CENTER><A HREF="ewtoc.html">Table of Contents</A> | <A HREF="about.html">Next</A></CENTER></P><A NAME="PAGENUM-24"><P>Page 24</P></A><A NAME="PAGENUM-25"><P>Page 25</P></A><H2>Introduction</H2><P>In 1996 a group of 80 SGML (Standard Generalized Markup Language)experts spent a hectic 11-week period developing a simplified version ofSGML that could be used on the World Wide Web. The aim was to provideWeb users with a means of defining their own tags and attributes when theywanted to, instead of being forced to use the HTML tagging scheme. ByNovember 1996, the World Wide Web Consortium SGML working group was readyto announce the first draft of XML—or Extensible Markup Language—atthe SGML 96 conference in Boston.</P><P>Since then, the XML language draft has been updated twice, and the firstdraft of the XML linking mechanism has been released. When complete, theXML standard will consist of three parts:</P><UL><LI> XML-Lang: The actual language that XML documents use.<LI> XML-Link: A set of conventions for linking within and betweenXML documents and other Web resources.<LI> XS: The XML style sheet language.</UL><P>Thus, XML will provide a complete, platform-independent and system-<BR>independent environment for the authoring and delivery of informationresources across the Web. It will support much richer hypertextual linking thanHTML offers.</P><P>In this book, we offer you an introduction to XML and a review of itsmain features. We show you some of the ways in which XML can and might beused, both on the Web and within intranets.</P><P><B>Who Should Read This Book?</B></P><P>If you're interested in the future of the World Wide Web, you need toread Presenting XML! This book is designed to cater to a range of levels ofinterest—from strategic overview to technical detail.</P><P>At the broadest level, this book aims to give an overview of the potential ofthe XML technology. This will be relevant to anyone considering how to getmore out of the World Wide Web, and anyone who is using Web technologywithin</P><A NAME="PAGENUM-8"><P>Page 8</P></A><P>an intranet. The successful deployment of XML could have a dramaticeffect on the way that the Web does its business: the relationship betweenclients and servers; the nature of information delivery and commerce on the Web; the whole concept of a Web site. As such, XML is a subject that cannot be ignoredby anyone who aims to do business, or simply deliver information, on the Web.</P><P>At a more detailed level, the book provides a thorough summary of whatXML actually is. For anyone who is considering the adoption of an XMLstrategy, this should be sufficient to gain a clear idea of the areas covered by XML and the capabilities that it offers. To achieve this, we examine the draft XMLstandard fairly closely and give an overview of what the three parts of theXML specification contain. We also provide examples of XML applications.</P><P><CENTER><TABLE BGCOLOR="#FFFF99"><TR><TD><B>NOTE</B></TD></TR><TR><TD><BLOCKQUOTE>Note: The XML specification is very much a moving target, but weare confident that the changes that are made from this point forward (andthere will be changes) will not affect the "big picture" in a major way.</BLOCKQUOTE></TD></TR></TABLE></CENTER></P><P>Throughout the book, we assume that the reader has some level offamiliarity with HTML coding, and we make comparisons between HTML andXML wherever relevant. This should help to establish the differences betweenXML and HTML, as well as build on existing knowledge. (However, extensiveknowledge of HTML is not a requirement to understand the book!)</P><P><B>How This Book Is Organized</B></P><P>Presenting XML is divided into four main parts and two appendixes.</P><P>Part I, "Introducing XML," gives a relatively self-contained overview and history of XML. It starts by explaining the concept ofgeneralized markup, of which XML is an example. It explains why HTML is unable to fulfill all the demands that are made on it, and the reasons something like XML is needed on the Web. The main advantages of XML are summarized, and the section ends with an outline of the resources that will be required to actually implement XMLapplications.</P><P>Part II, "XML in Detail," contains the technical stuff. In this section, wego through the XML language specification in detail and review its mainfeatures.</P><A NAME="PAGENUM-27"><P>Page 27</P></A><P>We then look more briefly at the other two aspects of the XMLspecification: linking and style sheets. Finally, we review the behavior that is expected of software that processes XML documents.</P><P>In Part III, "Using XML," we go back to the broader picture, and seehow XML might be put to practical use. This is tackled in a number of ways.</P><P>First, we look at a typical HTML page and see what needs to be done to itin order to make it valid as an XML document. The aim here is not tosuggest that anyone should be rushing off to convert all their HTML to XML! Itis meant to be an opportunity to understand some key differencesbetween HTML and XML, starting from a familiar format.</P><P>Next, we tackle a simple potential application of XML—for memos.This covers all the following essentials:</P><UL><LI> Writing a memo DTD<LI> Encoding a memo<LI> Using XML's powerful linking facilities<LI> Writing a simple style sheet</UL><P>After this, we paint a broad-brush picture of the potential role that XMLcan play in integrating diverse business systems and supporting Web-basedcommerce. Finally, we examine what effect XML is liable to have for aspecific application area, or vertical market. The area in question is that ofmuseum information systems. You will learn how XML can help to delivercomplex, structured museum information in a flexible and cost-effective manner.</P><P>Part IV, "The Future of XML," takes a look at how this new technologyis likely to shape up in practice.</P><P>We start with a review of the software that is emerging. In addition toXML-specific offerings, we look at packages that have their roots in SGML butare now providing significant functionality for XML applications.</P><P>Next, we review the issues that remain to be resolved in the XMLspecification. This review begins with a discussion of the common heritage thatSGML and XML share, and it goes on to review activities that contribute tothe completion of the XML specification. Finally, we look at how the existenceof XML is causing SGML itself to change and develop, with positiveimplications for XML.</P><A NAME="PAGENUM-28"><P>Page 28</P></A><P>We conclude with a review of real-world XML applications. Some of theseare actually up and running already, while others are still at the planningstage. The applications described give an interesting, even exciting, glimpse ofsome of the things that can and will be done with XML. No mean feat for astandard that isn't even complete!</P><P>The appendixes provide reference and supporting material.</P><P>Appendix A summarizes the differences between XML and SGML. This is,in effect, a list of the things that were left out of SGML in order to make XMLa viable proposition for the Web.</P><P>Appendix B lists references and sources of further information on XML.As with any W3C initiative, it is important to consult online sources for theup-to-date picture. This is particularly true for XML, given its relativelyincomplete state at the time of writing.</P><P>We have actually put theory into practice, by authoring this book inXML-like SGML, and using its inherent flexibility to deliver the message in avariety of media. The Sams.net Web site that supports this book, which can befound at the URL<A HREF="http://www.mcp.com/info/1-57521/1-57521-334-6">http://www.mcp.com/info/1-57521/1-57521-334-6</A>, containsan HTML version and a browsable SGML version. In addition, the samesource text was converted by an XML-like style sheet into Rich Text Format, sothat it could take its part in the normal copy-editing cycle at Sams.net andactually appear in printed form!</P><P><B>Conventions Used in This Book</B></P><P>In this book, we use some basic conventions for consistency. Whenpresenting actual XML markup, we use monospace type. This type is also used forfuller examples and listings that are given their own space, like this:</P><!-- CODE SNIP //--><PRE>fuller examples and listingsthat are given their own space</PRE><!-- END CODE SNIP //--><P>Beyond this type convention, we use sidebars to pick out important piecesof information. These take the following different forms:</P><A NAME="PAGENUM-29"><P>Page 29</P></A><P><TABLE><B>NOTE</B><BLOCKQUOTE> The Note sidebar is used to present an interesting piece ofinformation relating to the current topic.</BLOCKQUOTE></TABLE><BR><P><CENTER><TABLE BGCOLOR="#FFFF99"><TR><TD><B>WARNING</B></TD></TR><TR><TD><BLOCKQUOTE>The Warning sidebar flags issues and problems of which youshould be aware.</BLOCKQUOTE></TD></TR></TABLE></CENTER></P>TIP</B><BLOCKQUOTE> The Tip sidebar contains a handy tip or technique that you mightfind helpful.</BLOCKQUOTE></TABLE><P>Page 30</P></A><A NAME="PAGENUM-9"><P>Page 9</P></A><H2>Overview</H2><P> Foreword i</P><P> Introduction xxv</P><P><B>Part I Introducing XML 1</B></P><BLOCKQUOTE><P> 1 Markup in Theory and Practice 3</P><P> 2 Enter XML 19</P><P> 3 The XML Advantage 37</P><P> 4 Implementing XML 51</P></BLOCKQUOTE><P><B>Part II XML in Detail 65</B></P><BLOCKQUOTE><P> 5 The XML Approach 67</P><P> 6 Logical Structures in XML Documents 85</P><P> 7 Physical Structures in XML Documents 109</P><P> 8 Keeping It Tidy: The XML Rule Book 123</P><P> 9 Linking with XML 147</P><P> 10 The XML Style Mechanism 179</P><P> 11 The XML Processor 201</P></BLOCKQUOTE><P><B>Part III Using XML 211</B></P><BLOCKQUOTE><P> 12 Morphing Existing HTML into XML 213</P><P> 13 Developing an XML Memo Application 235</P><P> 14 Creating an XML Museum Information Application 263</P><P> 15 Automating the Web: Rapid Integration with XML 283</P></BLOCKQUOTE><P><B>Part IV The Future of XML 299</B></P><BLOCKQUOTE><P> 16 XML Software 301</P><P> 17 Resolution of the XML Specification 309</P><P> 18 Potential Applications of XML 331</P><P> A Differences Between SGML and XML 357</P><P> B Bibliography 373</P></BLOCKQUOTE><BLOCKQUOTE><P> Glossary 385</P><P> Index 393</P></BLOCKQUOTE><A NAME="PAGENUM-26"><P>Page 26</P></A><H2><A NAME="3346_ 19">Contents</A></H2><P> Foreword i</P><P> Introduction xxv</P><P><B>Part I Introducing XML 1</B></P><P> 1 Markup in Theory and Practice 3</P><P>What Is Markup? 4</P><P>What Is Generalized Markup? 5</P><P>SGML 6</P><BLOCKQUOTE><P>Structured Documents 7</P><P>Elements with Added Value: Attributes 8</P><P>Entities 9</P><P>SGML as a Metalanguage 10</P></BLOCKQUOTE><P>HTML as an SGML Application 10</P><BLOCKQUOTE><P>Syntax Conventions 11</P><P>DTD Design Approach 11</P><P>Internal and External Hyperlinking 12</P><P>SGML Conformance 13</P><P>The Advantages of HTML 14</P></BLOCKQUOTE><P>HTML: Where the Cracks Are Beginning to Show 15</P><BLOCKQUOTE><P>Displaying Extremely Long Pages 16</P><P>Providing Better Control Over Page Layout 17</P><P>Supporting Multiple Types of Hyperlinks 17</P><P>Delivering Any Type of Information 17</P></BLOCKQUOTE><P>Summary 18</P><P> 2 Enter XML 19</P><P>The Origin of XML 20</P><BLOCKQUOTE><P>The Grand Alliance 20</P><P>What Has the SGML WG Come Up With? 21</P></BLOCKQUOTE><P>XML Versus HTML 22</P><BLOCKQUOTE><P>The Role of XML 22</P><P>The Role of HTML 23</P><P>Browser Wars? 24</P></BLOCKQUOTE><P>XML-Lang: SGML Without Tears 25</P><BLOCKQUOTE><P>Self-Describing Documents 25</P><P>Clearer Is Simpler: Non-Minimized Markup 26</P><P>Create Your Own Applications 27</P></BLOCKQUOTE><A NAME="PAGENUM-10"><P>Page 10</P></A><BLOCKQUOTE><P>Valid and Well-Formed Documents 28</P><P>Entities: Documents in Chunks 29</P><P>Character Sets 30</P></BLOCKQUOTE><P>XML-Link: Power Linking 30</P><BLOCKQUOTE><P>Influences on the Design of XML-Link 30</P><P>Additional Information About Links 31</P><P>Simple and Extended Links 31</P><P>Locators 32</P></BLOCKQUOTE><P>XML-Style: Separate Style from Content 32</P><BLOCKQUOTE><P>Influences on the Design of XS 33</P><P>How XS Works 33</P><P>What's in an XS Style Sheet? 34</P><P>What XS Offers 34</P></BLOCKQUOTE><P>The XML Processor 35</P><P>Summary 36</P><P> 3 The XML Advantage 37</P><P>Documents that Know Themselves 38</P><BLOCKQUOTE><P>Header Information: The Owner's Handbook 38</P><P>Browseable Document Structure 39</P><P>Searchable Document Structure 40</P><P>Document Classes 41</P><P>Chunk Delivery 43</P></BLOCKQUOTE><P>XML-Based Authoring 44</P><BLOCKQUOTE><P>Elements and Styles 44</P><P>Rules and Local Declarations 46</P><P>The Revision Cycle 46</P><P>Link to Desktop Publishing 47</P></BLOCKQUOTE><P>XML and the Web 47</P><BLOCKQUOTE><P>The Empowered Publisher 47</P><P>The Empowered Client 48</P><P>Intranets Get Serious 49</P></BLOCKQUOTE><P>Summary 50</P><P> 4 Implementing XML 51</P><P>What Software Do You Need? 51</P><P>Authoring 52</P><BLOCKQUOTE><P>Parsers 55</P><P>DTD Editors and Browsers 56</P><P>Style Sheet Editors 57</P><P>Link Management Tools 59</P></BLOCKQUOTE><A NAME="PAGENUM-11"><P>Page 11</P></A><P>Conversion 59</P><BLOCKQUOTE><P>Converting to XML 60</P><P>XML to XML Conversions 61</P><P>XML to Other Formats 61</P></BLOCKQUOTE><P>Publishing 62</P><P>Site Maintenance 63</P>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -